A highly sensitive resist is required for the fabrication of x-ray membrane masks (1X) using electron-beam lithography. Current products require precise control of 175 nm critical dimensions with test features of 100 to 125 nm. UVIII, a chemically amplified positive resist designed for DUV processes, also functions as an electron-beam resist with sensitivities of 12 to 30 (mu) C/cm2, depending upon the bake parameters. This paper discusses the process and demonstrates the capability of the resist on membranes. The post-apply bake (PAB) and post-expose bake (PEB) affect the resist sensitivity and process latitude of UVIII. The process was defined using a statistically designed experiment (DOE) to optimize the PAB and PEB conditions. The figures of merit included resist sensitivity, dose latitude and resolution. When the patterning process was defined, the etch processes were developed for both the SiON hardmask and TaSi absorber. Features as small as 100 nm have been successfully transferred from UVIII resist into the TaSi membrane with critical dimension (CD) uniformity of less than 20nm 3(sigma) within a mask. The process latitude, high resolution, and excellent CD uniformity indicate the UVIII resist is compatible with the manufacturing environment required for the fabrication of x-ray membrane masks.